Assume that plant weight is determined by a pair of alleles at each of two independently assorting loci (A and a, B and b) that are additive in their effects. Further assume that each allele represented by an uppercase letter contributes 4 g to weight and that each allele represented by a lowercase letter contributes 1 g to weight. If a plant with genotype AA BB is crossed with a plant with genotype aa bb, what weights are expected in the F, progeny?

a.1g
b. 4g
c. 8g
d. 10g
e. 16g